Lock:Timeout Event Class


Applies To: SQL Server 2016

The Lock:Timeout event class indicates that a request for a lock on a resource, such as a page, has timed out because another transaction is holding a blocking lock on the required resource. Time-out is determined by the @@LOCK_TIMEOUT system function and can be set with the SET LOCK_TIMEOUT statement.

Use the Lock:Timeout event class to monitor when time-out conditions occur. This information is useful to determine if time-outs are significantly affecting the performance of your application, and which objects are involved. You can examine the application code that modifies these objects to determine if changes to minimize time-outs can be made.

Lock:Timeout events with a duration of 0 are commonly the result of internal lock probes and are not necessarily an indication of a problem. The Lock:Timeout (timeout > 0) event can be used to ignore time-outs with a duration of 0.

Data column nameData typeDescriptionColumn IDFilterable
ApplicationNamenvarcharName of the client application that created the connection to an instance of SQL Server. This column is populated with the values passed by the application rather than the displayed name of the program.10Yes
BinaryDataimageLock resource identifier.2Yes
ClientProcessIDintID assigned by the host computer to the process where the client application is running. This data column is populated if the client provides the client process ID.9Yes
DatabaseIDintID of the database in which the lock time-out occurred. SQL Server Profiler displays the name of the database if the ServerName data column is captured in the trace and the server is available. Determine the value for a database by using the DB_ID function.3Yes
DatabaseNamenvarcharName of the database in which the time-out occurred.35Yes
DurationbigintAmount of time (in microseconds) between the time the lock request was issued and the lock was timed out.13Yes
EndTimedatetimeTime at which the event ended.15Yes
EventClassintType of event = 27.27No
EventSequenceintThe sequence of a given event within the request.51No
GroupIDintID of the workload group where the SQL Trace event fires.66Yes
HostNamenvarcharName of the computer on which the client is running. This data column is populated if the client provides the host name. To determine the host name, use the HOST_NAME function.8Yes
IntegerData2intIdentified for informational purposes only. Not supported. Future compatibility is not guaranteed.55Yes
IsSystemintIndicates whether the event occurred on a system process or a user process. 1 = system, 0 = user.60Yes
LoginNamenvarcharName of the login of the user (either SQL Server security login or the Microsoft Windows login credentials in the form of DOMAIN\username).11Yes
LoginSidimageSecurity identification number (SID) of the logged-in user. You can find this information in the sys.server_principals catalog view. Each SID is unique for each login in the server.41Yes
ModeintThe resulting mode after the time-out.

0=NULL - Compatible with all other lock modes (LCK_M_NL)

1=Schema Stability lock (LCK_M_SCH_S)

2=Schema Modification Lock (LCK_M_SCH_M)

3=Shared Lock (LCK_M_S)

4=Update Lock (LCK_M_U)

5=Exclusive Lock (LCK_M_X)

6=Intent Shared Lock (LCK_M_IS)

7=Intent Update Lock (LCK_M_IU)

8=Intent Exclusive Lock (LCK_M_IX)

9=Shared with intent to Update (LCK_M_SIU)

10=Shared with Intent Exclusive (LCK_M_SIX)

11=Update with Intent Exclusive (LCK_M_UIX)

12=Bulk Update Lock (LCK_M_BU)

13=Key range Shared/Shared (LCK_M_RS_S)

14=Key range Shared/Update (LCK_M_RS_U)

15=Key Range Insert NULL (LCK_M_RI_NL)

16=Key Range Insert Shared (LCK_M_RI_S)

17=Key Range Insert Update (LCK_M_RI_U)

18=Key Range Insert Exclusive (LCK_M_RI_X)

19=Key Range Exclusive Shared (LCK_M_RX_S)

20=Key Range Exclusive Update (LCK_M_RX_U)

21=Key Range Exclusive Exclusive (LCK_M_RX_X)
NTDomainNamenvarcharWindows domain to which the user belongs.7Yes
NTUserNamenvarcharWindows user name.6Yes
ObjectIDintID of the object which was timed out, if available and applicable.22Yes
ObjectID2bigintID of the related object or entity, if available and applicable.56Yes




RequestIDintID of the request containing the statement.49Yes
ServerNamenvarcharName of the instance of SQL Server being traced.26No
SessionLoginNamenvarcharLogin name of the user who originated the session. For example, if you connect to SQL Server using Login1 and execute a statement as Login2, SessionLoginName shows Login1; while LoginName shows Login2. This column displays both SQL Server and Windows logins.64Yes
SPIDintID of the session on which the event occurred.12Yes
StartTimedatetimeTime at which the event started, if available.14Yes
TextDatantextText value dependent on the lock type that was being acquired when the time-out occurred.1Yes
TransactionIDbigintSystem-assigned ID of the transaction.4Yes













sp_trace_setevent (Transact-SQL)
Lock:Timeout (timeout > 0) Event Class
sys.dm_tran_locks (Transact-SQL)

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